The Large Immortal Machine and the Ticking Time Bomb

35 Pages Posted: 26 Mar 2012 Last revised: 5 Apr 2012

Date Written: March 23, 2012


Designers of the first electronic telephone switches nicknamed them the "large immortal machines" because switches last decades. The 1994 Communications Assistance for Law Enforcement Act (CALEA) requires that all digital-switched telephone networks be built wiretap enabled; the law took longevity of switches into account by authorizing funding to update switches in place. But by failing to analyze how threat models would change in a highly connected IP-based world, CALEA did not consider the longevity of switches prospectively. As an architected security breach, CALEA compliance is a ticking time bomb. This paper discusses how this situation arose, and what policy the Federal Communications Commission should be following the alleviate the problem.

Keywords: communications, wiretap, interception, CALEA, security, telephone switch

Suggested Citation

Landau, Susan, The Large Immortal Machine and the Ticking Time Bomb (March 23, 2012). Available at SSRN: or

Susan Landau (Contact Author)

Tufts University ( email )

Medford, MA 02155
United States

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